1. Field
The present disclosure relates to methods of amplifying telomeres of genomic DNA and compositions and kits for amplifying telomeres of genomic DNA used therefor.
2. Description of the Related Art
In eukaryotic cells, lagging strands of DNA get shorter by DNA amplification due to an end replication problem related to the DNA amplification. This is caused as a result of a DNA replication mechanism. During replication of a lagging strand, a short RNA sequence acting as a primer binds ahead on the lagging strand. DNA polymerases initiate replication from several origins of replication forming Okazaki fragments. Several RNA primers bind to one lagging strand of DNA, and DNA polymerases and DNA ligases come along to convert the RNA primers to DNA, and to seal the gaps between the Okazaki fragments. In order to replace the RNA with DNA, a DNA fragment should be located at a region directly upstream from the RNA primer. This occurs at every locations of the lagging strand except for an end of chromosome to which a last RNA primer binds. As a result, the RNAs are degraded by RNases which degrade RNA on DNA, and the telomere that is an end portion of chromosomal DNA is partially lost during each cycle of replication. When telomeres in a cell get too short, the cell can no longer replicate and apoptosis occurs. Thus, the length of the telomere is estimated as a factor determining aging and life span and estimated to be related to prevention of cancers.
Due to roles of telomeres in cancers and aging-related diseases, information about lengths of telomeres is required. The lengths of the telomeres may be determined by telomere restriction fragment length assay (TRF), primer extension assay, quantitative polymerase chain reaction (q-PCR), single telomere elongation length analysis (STELA), universal STELA, and the like. However, there remains a need to develop improved methods of determining the length of a telomere of genomic DNA with high efficiency and high sensitivity.